Portable solar panel for heating air

ABSTRACT

A solar heater comprises one or more portable panels for collecting heat from the sun and providing it to a space to be heated. The panels include collector plates within a double glazed frame. The collector plate is formed of black corrugated steel, and heats up quickly in the sun. A blower blows air into an input manifold and across the collector plate, perpendicular to the corrugations, and the heated air exits via an output manifold. A sensor controls when the blower operates.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to portable panels for heating forced air with solar radiation.

2. Description of the Related Art

Solar energy is very effective for heating living and working spaces. Passive solar heating, such as sun falling on a roof or window, will heat the space inside. But to effectively heat the inside space, at selected times, apparatus is required.

Active solar heating systems use electrical or mechanical equipment to increase the amount of usable solar heat provided to the space to be heated (generally called living space, although it includes garages and offices and the like). For example, fans might deliver heated air to the living space.

Photovoltaic array may also be used for heating, but converting sunlight into electricity and then back to heat is inefficient. However, the ability to store the energy in a battery is an advantage.

A need remains in the art for improved active solar heating panels for providing heat to a living space.

SUMMARY

An object of the present invention is to provide active solar heating panels for providing heat to a living space. Individual solar heating panels according to the present invention are generally portable, and are configurable into arrays.

Each solar panel includes a frame with a panel backing for retaining a collector sheet and glazing to allow the sun to reach the top surface of the collector. The collector sheet is generally parallel to the backing and the top layer, and spaced apart from each.

The frame includes side walls. An input side wall includes air holes for air to enter the panel, and an output side wall includes air holes for air to exit the panel. The collector plate bisects the input and output air holes such that air travels over both the top surface and the bottom surface of the collector plate.

As a feature, the collector plate may be textured to increase turbulent airflow. The collector plate is generally black and may comprise corrugated steel.

The glazing may include an acrylic glass (such as Plexiglas®) outer layer and a regular window glass inner layer (e.g. silicate glass). The acrylic glass protects the glass from the elements, while the window glass is cheaper and stands up to the high internal temperatures of the panel better. Alternatively, the outer layer could comprise safety glass or tempered glass or the like.

The frame may be composed of composite and include grooves for holding the collector sheet and glazing layers in place.

The solar panels are designed to be configured into arrays. Straight-through panels have air holes on opposing sides, while corner panels have air holes on adjacent sides.

Air is forced into air holes in an entrance panel on one side of the array, travels through each panel in turn, and exits through air holes in an exit panel.

Equipment for forcing air through the array may include a fan, input and output air manifolds, and tubing. A temperature sensor monitors air leaving a panel or array and provides data to a control unit, which controls the fan according to the data. Power to the fan might be provided via an electrical outlet, a battery, a photovoltaic cell, or the like.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an isometric view of a solar panel according to the present invention.

FIG. 2 is a magnified section view of the panel of FIG. 1.

FIG. 3 is a side view of an end of the panel of FIG. 1.

FIG. 4 is an exploded isometric view of the panel of FIG. 1.

FIG. 5 is plan view of a solar heater formed from multiple solar panels according to the present invention.

FIG. 6 is a block diagram showing the present invention in use.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The following reference numbers are used in the figures:

100 Solar panel - straight-through 102 Panel frame 104 Air holes 106 Acrylic glass panel 108 Glass panel 110 Collector sheet 112 Panel backing 114 Acrylic glass panel groove 116 Glass panel groove 118 Collector sheet groove 119 Recess for backing 120 Panel sides with air holes 122 Panel sides without air holes 130 Multipanel heating unit 132 Input air manifold 134 Output air manifold 136 Gasket 140 Solar panel - corner 150 Fan 152 Input tubing from fan 158 Input air from fan 160 Output heated air from unit 162 Air path 170 Heater 172 Temperature sensor 174 Control signal from heating unit 176 Control signal from heated space

FIG. 1 is an isometric view of an exemplary single straight-through solar panel 100 according to the present invention. Panel 100 includes a frame 102 having air holes 104 through which air will enter and leave the panel. Frame 102 includes sides 120 with air holes and sides 122 without air holes. Panel 100 is preferably double glazed with a layer of acrylic glass 106 and a layer of glass 108. The top panel 106 is acrylic glass to resist hail and other damage. Acrylic glass is 10 times stronger than glass. The interior glazing layer 108 is glass to resist heat better and because it is cheaper. Beneath the glazing 106, 108 is a collector sheet 110 of black corrugated steel for collecting heat from the sun. Beneath sheet 110 and attached to frame 102 is backing 112.

Corrugated sheet 110 is preferably generally centered with respect to air holes 104, so that air flows over and under sheet 110. The corrugations run perpendicular to the airflow to cause turbulent airflow and increase heat transfer.

FIG. 2 is a magnified section view of a side 122 of panel 100. Side 122 forms grooves 114, 116, 118 for holding glazing 106, 108 and corrugated sheet 110 respectively. Backing 112 is affixed to the bottom of panel 102 in recess 119.

FIG. 3 is a side view of frame 102 side 120. Side 120 includes air holes 104 and grooves 114, 116 and 118. Preferably, a recess 119 is formed in the bottom of side 120 for insertion of backing 112.

FIG. 4 is an exploded isometric view of panel 100. Frame 102 is formed of sides 120 having air holes and sides 122 without air holes. In the straight-through panel 100, two sides 120 with air holes are positioned opposite to each other. Ambient air 158 will enter one side 120 via air holes 104, pass over corrugated sheet 110 perpendicular to the direction of the corrugations, and exit panel 100 through the second side 120 through its air holes 104. FIG. 4 also shows how panel 100 might be assembled. Glazing 106 and 108 is fitted into grooves 114 and 116. Corrugated sheet 110 is fitted into groove 118. Sides 120, 122 are then fastened together, for example with glue or nails, forming frame 102. Then, backing 112 is affixed to the bottom of frame 102.

In a preferred embodiment, each panel 100 is portable, i.e. compact and light enough to be carried and installed by a single person. For example, Panel 100 is two feet square and 3 inches thick. It weighs about 20 pounds. Frame 102 is formed of a light tough material such as the weatherproof composite used for decking. The frame is ¾ inch thick. Air holes 104 are 1¼ inch in diameter. Collector plate 110 is corrugated steel with 1¼ inch corrugations, and is painted black on the top surface (facing the glazing). Backing 112 is tempered masonite, ⅛ inch thick.

Panels 100 are tough and portable. Panels manufactured as described above have been tested to temperatures above real world conditions, intense rain and snow, and direct sunlight without failures. Panels dropped from heights of less than 6 feet generally have unharmed frames, though the window glass layer breaks around 25% of the time (the broken glass was contained within the panel structure in these cases).

FIG. 5 is plan view of a solar heater formed from multiple solar panels 100, 140. Corner panels 140 are similar to straight-through panels 100, except that sides 120 with air holes 104 are adjacent to each other instead of across from each other. Hence input air 158 enters manifold 132, follows path 162 through heater 130 and exits manifold 134 as heated airflow 160. A thin rubber gasket 136 between each connected panel 100, 140 seals airflow within heater 130.

Those skilled in the art will appreciate that panels 100, 140 may be connected in various combinations as heating requirements dictate and space allows. For example, several straight-through panels 100 may be connected in a row where a long narrow space is available. A heater may be formed of a single panel (see FIG. 6) or two or several. A four-panel array has been observed to raise air temperature 35 degrees at 120 CFM. An array of six panels provides about half of the heat needed for a 400 ft² room or garage, if no heat storage system is used. As an option, a heat storage system for storing heat during the day for use at night might comprise storage modules, for example 2 foot cubes made of weatherproof composite boxes filled with recycled concrete broken into first sized chunks. The boxes connect together with short pieces of flex duct and are ducted back to the blower box, where dampers control the flow of air to charge them up with heat during the daytime and recover the heat at night.

The storage modules could be stacked in a basement, assembled outside along a wall, or even placed on the uneven ground under a mobile home.

Panel arrays may be mounted on any sunny wall or roof or on a rack. Panels may be arrayed around a window or along the skirting of a mobile home. Each array includes an input manifold 132, connected to blower 150, and an exit manifold 134 for providing heated air 160 to the space to be heated, for example via a flexible duct (not shown). Panels 100, 130 may be adjacent to each other as shown in FIG. 5, or they may be connected via tubing. In the latter case each panel includes manifolds 132, 134.

FIG. 6 is a block diagram showing the present invention in use. A blower 150 provides input airflow 158 to heater 170, comprising a single straight-through panel 100, via tubing 152 and input manifold 132. Heated exit airflow 160 exiting heater 170 is available for use in heating.

Blower 150 may be mounted in a box designed to insert into a window much like a standard window air conditioner. It could mount horizontally on the sill of a double or single hung window, or vertically in a slider. It could also be installed in an opening cut into the exterior wall if the user so desires. If the user wants to cut openings in the roof to run the ducts through, blower 150 could even be mounted on an interior wall anywhere in the building. Blower 150 might comprise a 120 volt squirrel cage model which plugs into any interior outlet. An optional 12 volt DC model is powered by a photovoltaic panel (not shown). This would allow use of the system anywhere in the world and when a power outage occurs as long as it is exposed to sunlight. The blower moves up to 250 CFM of air and is controlled by a variable speed switch. Sensor 172 near or within discharge manifold 134 of heater 100 prevents heated air 160 from entering the space to be heated when the temperature 174 in heater 100 is lower than the current temperature 176 of that space. In one embodiment, sensor 172 prevents fan 150 from running if the temperature of the air in heater 100 falls below 95° F. As a feature, a bypass switch may be provided so the owner can draw cooler air if desired.

It will be appreciated by one skilled in the art that there are many possible variations on these designs that fall within the scope of the present invention. 

1. An active solar heating panel comprising: a frame having sides, a top, and a bottom; backing attached at the bottom of the frame; glazing attached at the top of the frame; air holes formed in two sides of the frame; and a collector sheet attached between the backing and the glazing, the collector sheet positioned to divide the air holes.
 2. The panel of claim 1 wherein the collector sheet is textured to increase turbulent air flow.
 3. The panel of claim 2 wherein the collector sheet is corrugated.
 4. The panel of claim 3 wherein the collector sheet corrugations run generally perpendicular to airflow through the panel.
 5. The panel of claim 1 wherein the glazing comprises an upper acrylic glass layer and a lower silicate glass layer.
 6. The panel of claim 5 wherein the sides include grooves holding the collector sheet and the glazing in place.
 7. An active solar array comprising: detachable solar panels including— a frame having sides, a top, and a bottom; backing attached at the bottom of the frame; glazing attached at the top of the frame; input air holes formed in one side of the frame and exit holes formed in another side of the frame; and a collector sheet attached between the backing and the glazing, the collector sheet positioned to divide the air holes, the collector sheet textured to increase turbulent airflow; wherein the input air holes of an input panel are positioned to form an input to the array, the exit air holes of an output panel are positioned to form an output to the array, and wherein the panels are arranged such that the exit air holes of each panel except the output panel are aligned to the input air holes of an adjacent panel.
 8. The array of claim 7 further comprising a fan for providing input air to the input holes of the input panel.
 9. The array of claim 8 further comprising a duct connected at the exit holes of the output panel for removing air from the array and providing it to a living space.
 10. The array of claim 9 further comprising: a temperature monitor for measuring temperature near the exit holes of the output panel; and control circuitry for controlling the fan based upon the measured temperature near the exit holes of the output panel.
 11. The array of claim 10 further comprising a living space thermometer for measuring the temperature within the living space and wherein the control circuitry further controls the fan based upon the temperature within the living space.
 12. The array of claim 10 further comprising: a storage module containing material that stores heat; storage ducting to provide air from the exit holes of the output panel to the storage module; and a damper for selectively directing air to the storage module; wherein the control circuitry further controls the damper.
 13. A method for providing heated air to a living space comprising the steps of: providing a first active solar panel including— a frame having sides, a top, and a bottom; backing attached at the bottom of the frame; glazing attached at the top of the frame; input air holes formed in one side of the frame and exit air holes formed in another side of the frame; and a collector sheet attached between the backing and the glazing, the collector sheet positioned to divide the air holes; positioning the panel such that the sun shines through the glazing onto the collector sheet; providing airflow into the input air holes to flow over and under the collector sheet and exit the exit air holes; supplying air flow from the output air holes to the living space; monitoring air temperature near the exit air holes; and controlling the air flow provided according to the monitored temperature.
 14. The method of claim 14 further comprising the step of: connecting a second active solar panel to the first such that the exit air holes of the first connect to the input air holes of the second.
 15. The method of claim 13 further comprising the step of: providing air from the exit holes to a living space.
 16. The method of claim 15 further comprising the step of measuring the temperature within a living space and also controlling the air flow based upon the temperature within the living space.
 17. The method of claim 16 further comprising the steps of selectively directing air flow from the exit holes to a storage module and storing heat within the storage module.
 18. The method of claim 17 further comprising the step of directing air flow from the storage module to the living space.
 19. The method of claim 13, further including the step of corrugating the collector sheet. 